The Darkness is one of the main series from Top Cow, something of a companion series to Witchblade as it exists in the same universe. It is about Jackie Estacado, an ex-mobster and the wielder of the Darkness, an ancient evil force and a major player in the Witchblade cosmology (or so Wikipedia tells me).
The story is about Estacado's attempts to rule a small, fictitious South American country called Sierra Munoz where he overthrew the previous dictator and supports himself with a drug he created using the Darkness, called Nightfall. He is aided by a scientist named Kirchner who, after studying the Darkness, teaches Estacado how to use it to do things like create water or drugs, among other things. Over the course of the story, Estacado slowly loses control over the country due to a rebellion, which is aided by private military contractor from the US. At the same time Estacado is betrayed by Kirchner and Elle, a woman Estacado created using the Darkness. The story ends after Estacado kills the Darkness incarnate that was born from Elle.